kidney & urinary system

Outlines Structure of kidney & urinary system Functions of kidney Renal function tests Clinical manifestations of renal diseases

Acute renal failure Chronic renal failure Glomerular syndrome

Diseases of the kidney Glomerulonephritis

Structure of kidney & Urinary system

Kidney: Cortex, Medulla

Nephron1. Glomerulus : highly permeable

H2O, electrolytes filtration size + charge2. Proximal convoluted tubules (PCT):

reabsorb H2ONa+, K+, H+, Cl

3. Loop of Henle : - function as PCT - descending (no H2O) - ascending H2O4. Distal convoluted tubules (DCT) : - Aldosterone dependent - Na+ reabsorption - K+ excretion - Synthesis - carbonic anhydrase H + ~ pH & electrolytes5. Collecting ducts : - ADH (antidiuretic hormone) H2O reabsorption

1. Water balance

Osmoreceptor (hypothalamus)

ADH, Vasopressin (Pituitary)

Collecting duct

Absorption of H2O

Function of Kidney

2. Acid-base balance

Carbonic anhydrase (Distal tubules)

Carbonic acid-bicarbonate buffer system

H+ excretionNa+ reabsorptionH2O excretion

3. Excretion of waste product

- Acid - base - H2O

- creatinine

- Metabolites

4. Others - erythropoeitin

Conclusion : renal functions Filtration Reabsorption Secretion

Renal function tests

1. Clearance Value : Creatinine, inulin clearance

GFR (glumerular filtration rate)

= Cr urine x Volume urine / min

Cr in plasma

= 120 ml / min/body areas

2. Blood urea nitrogen (BUN) - food - massive destruction of kidney

Renal function tests & Diagnosis

Urinalysis

Physical & chemical properties

- pH, Specific gravity (1.022), protein, sugar, etc.

Urine sediments - Cell-RBC, WBC, Renal cells, etc.

- Urine casts

- Crystalline structure

Urinalysis profiles

Specific gravity 1.001 - 1.035

Osmolarity500 - 800 mOsm / kg water

pH 4.7 - 8.0

Volume 600 - 1500 ml / 24 hr

RBC 0- 1,000,000 / hours

WBC 0- 1,000,000 / hour

Tubular cells 10,000 - 200,000 / hour

Casts 0- 5,000 / 24 hours

Hyaline cast : clear, tubular protein

Granular cast : high protein from plasmaWaxy cast : degraded granular cast

Red cell cast : glomerular disease

Fatty cast : tubular damage

WBC cast : pyelonephritis

Bacteriological examination

Renal biopsy

Radiologic examination

Plain KUB

Intravenous pyelography (IVP)

Granular cast

Waxy castWaxy cast

Red cell cast

Acute renal failure

: urine < 400ml / 24 hr (Oliguria) or > 50-100 ml / 24 hr (anuria)

Cause :

1. Hemodynamic changes : low blood volume to kidney

- hemorrhage, burn

- high hemoglobin, myoglobin

2. Nephrotoxic injury

- Ischemic - PCT, DCT damage

- Poison - CCI4 , Hg

- Infection - Leptospirosis , yellow fever

Clinical manifestations

Effects of acute renal failure

Oliguria

Anuria

Uremia

BUN, K+ , PO4

Metabolic acidosis

Chronic renal failureCauses : glomerulonephritis, chronic pyelonephritis,

nephrosclerosis, lupus erythematosus,

diabetes, renal tuberculosis

decreased renal function

Effects : Uremia syndrome

1. General symptom : Lethargy, insomnia, etc.

2. CVS : hypertension, edema, sterile fibrinous

pericarditis

3. GI : เบื่��ออาหาร, อาเจียน - gastritis, colitis (NH3)

4. CNS : Lethargy (ซึ�ม), peripheral neuropathy

5. Anemia : Specific for uremia

6. Infection : UTI, Sepsis

7. Metabolic acidosis : หายใจีหอบื่

Glomerular syndromeNephrotic syndrome

Nephritic syndrome

Chronic renal failure

Nephrotic syndrome

Severe proteinuria > 0.15 gm / day upto 10 g / d

Hypoproteinemia

Generalized edema

Hyperlipidemia > 250 mg %

Nephritic syndrome

Hematuria

Oliguria

Azotemia : high Creatinine + BUN

Hypertension : obstruction of capillary

Diseases of Kidney

Glomerulonephritis 1) Primary glomerular diseases

Glomerular diseases causing nephritic

syndrome Diffuse acute proliferative glomerulonephritis (APGN) Rapidly progressive (crescentic) glomerulonephritis

(RPGN) Focal glomerulonephritis (FGN)

Glomerular diseases causing nephrotic syndrome (Diffuse) minimal change diseases Membranous nephropathy (MGN) Membranoproliferative glomerulonephritis (MPGN) Urinary tract stones

Glomerular diseases causing chronic

renal failure Chronic glomerulonephritis

2) Secondary glomerular diseasesDiabetes mellitus, systemic lupus erythematosusamyloidosis, etc.

Histologic alterations

1) Hypercellularity

Cellular proliferation : mesangium, endothelium,

parietal epithelium

Leukocytic infiltration : Neutrophils, monocytes

Formation of crescent : Parietal epithelium + PMN

2) Basement membrane thickening : LM, EM

Immune complex deposition : Subendothelium,

intramembranous, subepithelium

Fibrin amyloid : GBM

3) Hyalinization and sclerosis

Diffuse : involve all glomeruli

Focal : some glomeruli

Global : involve the entire glomerulusaffecting a past of glomerulus

Glomerular disease with nephrotic syndrome

Minimal changes (Lipoid nephrosis) 2 - 6 yrs child with nephrotic syndrome

Etiology : unknown - immunologic mechanism affect

visceral epithelium

Pathology :Normal glomeruli (LM)Foot process loss (EM) No immune complexRenal tubules (proximal) - lipid

Clinical : Proteinuria, edema, no hypertension

Most-respond to corticosteroid

Minimal changes (Lipoid nephrosis)

Membranous nephropathy

Common nephrotic syndrome in adult

Etiology : unknown - drugs (NSAIDS), infection, SLE

Pathology : Diffuse thickening GBM (LM)

Subepithelium deposits

Ig deposit c complement

Clinic : Proteinuria

BUN progress

~ 10% chronic renal failure die

Membranoproliferative Glomerulonephritis (MPGN)

- Basement membrane thickening, increased glomerular cells ,

Leukocyte infiltration

- Children + young adults

Pathology :

- Hypercellular + large (Mesangium, WBC?)

- Lobular glomeruli

- thickened GBM double contour (tram- track)

- subendothelium deposit

- IgG, C3

Clinical : - NS, some with hematuria

~ 50% chronic renal failure 10 yrs